Camera shutter



Jan. 1, 1946. J. TERRETT ET AL.

CAMERA SHUTTER Filed April 3, 1945 3 Sheets-Sheet l Jan. 1, 1946. v J.TERETT ETAL 2,392,071

CAMERA SHUTTER Filed April 5, 1943 3 Sheets-Sheet 2 I 7 4 5& 5,9 92 5015/ /07 Jan. 1, 1946.

J. TERRETT ET AL.

CAMERA SHUTTER s Sheets-Sheet 5 Filed April 3, 1945 Patented Jan. 1,1946 CAMERA SHUTTER Joseph Terrett and William Barton Wood, Sutton,England, assignors to Purma Cameras Limited,

Sutton, England Application April 3, 1943, Serial No. 481,766

In Great Britain November 26, 1941v Claims. (01. 9557) This inventionrelates to cameras and especially to those having shutters which requireto be wound or set in readiness for making each exposure. The termwinding is used broadly in this specification in connection with theshutter to denote the operation by which the energy which is required tomake the shutter perform the exposing action, is imparted to and storedin a spring or like resilient device in readiness for the release of theshutter. The winding of the shutter may be performed by other than arotary motion.

It is an object of the present invention to provide an improved andrelatively simple form of shutter mechanism which can readily becombined with the film-winding mechanism of a roll film camera wherebythe Operations of setting th shutter and winding the film may beperformed simultaneously by the actuation of a single member.

It is a further object of the invention to provide an improved form ofshutter and film winding mechanism incorporating locking means adaptedto arrest automatically the winding of the film when the picture arearequired for the next exposure has been brought into position, theaction of releasing the shutter to make the exposure being adapted tobring said locking means back into operation.

According to one aspect of the invention, there is provided a camerashutter in which a pair of meshing gear wheels, used for winding theshutter, are urged resiliently into engagement so as to slip when thedriven wheel reaches a predetermined position, wherein the driven gearwheel is provided with a deflector member which is movablecircumferentially relative to said driven gear wheel and which acts tomove the gear wheels apart out of mesh when the driven gear wheelreaches the said predetermined position during the winding of theshutter. This mechanism can advantageously be provided in conjunctionwith a shutter of the roller-blind type, preferably one which isarranged to operate just in front of the focal plane of the camera.

- In aroll film camera having a shutter which requires winding prior tooperation, according to a further feature of the invention winding ofthe film also winds the shutter through gearing, the arrangementbeing'such that when the shutter is fully wound, slip is permitted toenable the winding movement of the film to be completed.

There is further provided according to the invention a roll film cameracomprising in combination a common windingmember serving to windsimultaneously both the shutter and the film, re-

leasing means for the shutter, indicating means responsive to the extentto which the-film is wcund and interlocking means, which restrictmovement oflthe winding member, are unlocked by release of the shutter,and are controlled by the indicating means.

a As a stillfurther aspect of the invention a roll film camera having ashutter with winding means is characterised by the fact that saidwinding means serves also to wind the film and includes a pair ofmeshing gear wheels urged resiliently into engagement, the driven gearwheel being provided with a deflector member which is movablecircumferentially relative to the said driven wheel and which acts tomove the gear wheels apart out of mesh when the driven gear wheelreaches a predetermined position.

The invention is illustrated by way of example in the accompanyingdiagrammatic drawings, in which:

Figure 1 is a plan of an improved roll film camera;

Figure 2 is a sectional plan drawn to an enlarged scale and showing thegeneral arrangement of the shutter and film winding mechanism, togetherwith automatic interlocking means;

Figure 3 is a diagram showing in plan the mechanism used for winding theshutter, the latter being in its releasedhposition;

Figure 4 is a rear elevation of the shutter mechanism, the spacing ofthe parts being exaggerated to show the action more clearly;

Figure 5 is a plan of the first latch member;

Figure 6 is a plan of the second latch member;

Figure '7 is a view corresponding to Figure 3, but showing the positionoccupied by the parts when the shutter has been fully wound but the filmwinding is as yet incomplete;

Figure 8 is a similar view with the shutter in process of'being'released to give an instantaneous 'exposure; 1

V Figure 9 is a rear sectional elevation ofthe indicating mechanism;

Figure 10 is a plan of the interlocking means, the parts being shown inthe positions which they occupy when'the shutter has been wound, but thefilmwinding is incomplete; and

Figure l1 is a similar view with the winding mechanism locked,the'camera thus being ready for the next exposure to be made.

The roll film camera shown in Figure 1 comprises a hollow body 10 havingfitted to its front vision view finder is conveniently provided at l5. Aknob iii mounted upon a spindle ii is rotatable in the direction shownby the arrow so as to wind the shutter and simultaneously wind the himso as to bring the next picture area of the film into position forexposure. The film itself is indi cated in dotted lines at 8 and passesin the usual way from a supply film spool E9 to a receiving film spool23, said film It hrst running in driving engagement against a roller 2|belonging to indi-' cating mechanism, which will be hereinafterdescribed, while adjacent the other end oithe camera a hired orrotatable guide roller.- 22 is provided in the usual manner. In the top23 of the camera body it a window or opening 24 is provided throughwhich the appropriate numeral upon an indicating disc 25 is renderedvisible so as to show to the user how many times the him has been woundforward for the purpose of making exposures. The indication through thewindow 24 can. be returned to "1 by operating a knob 26, as will behereinafter explained. Also fitted to the top oi the camera body lil isa speed setting knob 27 for use in regulating the exposure time again bythe shutter; an annular flange 28 is married with a scale which can beread in conjunction with an index 29 when the shutter is unwound or withan index 30 when the shutter is in a wound condition. The usual shutterreleasing plunger is indicated at 3 l.

The generalarrangement of the internal mechanism is showndiagrammatically in Figure 2. and will now be described briefly; thearrangement and operation of the various sections of the mechanism willbe more clearly understood Irom the description appertaining to thesucceeding ngures. The usual two spring roller blinds, which togetherconstitute the shutter or the sell-capping 'Iocal plane type, areindicated at and its; the usual spring rollers belonging to these blindsare indicated at 34 and 35 and the winding rollers at 3B and 31respectively. The rollers to and 3'! are wound by means of pinions 38and 39, which respectively mesh with a pair or gear wheels 4d and 4| theformer being partly broken away in Figure 2. The gear wheels 40 and 41are rotatable independently of one another upon a spindle 53, whichlatter carriesthe speed setting knob 21 and is also independentlyrotatable; it is also freely slidable in an axial direction. In normalmesh with the upper gear wheel eu is a "uriving gear w eel 42 carried bythe free end of an angular-1y movable arm 43, which latter is pivotedfreely about the axis of the spindle l'l carrying the winding Knob l6\Figure l) There are two gear wheels securely fastened to the spindlell, namely an upper gear wheel 44 in permanent mesh with the gear wheel42 and a smaller lower gear wheel 45 which is in permanent mesh with agear wheel 46, the latter being arranged to drive the receiving filmspool 20 (Figure 1). A ratchet pawl 4! urged into engagement with thegear wheel 46 by aspring (not a pinion 6b which meshes with a gear wheel6| mounted for free rotation upon an arm 62; this arm i itself mountedfreely upon the spindle of the roller 2| and pinion 60. Fastened to thegear wheel M is a gear wheel 63 arranged to mesh with a gear wheel 64fastened beneath the indicator disc 65 (see also Figure 9). A few of theteeth of the gear wheel 64 are cut away, as indicated at shown) servesto prevent unwinding of thespool 20 and also has a holding action on theshutter blinds 32 and 33 while these are being wound. Means forreleasing the shutter comprise briefly a releasing lever 48, a firstlatch member 49 and V 65, so that when the gear wheel 64 and indicatordisc 65 have been driven through nearly one complete revolution in theanti-clockwise direction by the gear wheel 63 the latter reaches thecutaway portion 66' and therefore ceases to drive the gear wheel 64. Theabove-mentioned anti-clockwise rotation of the disc 65 and gear 'wheel64 takes place against the action of a coiled spring 61 (Figure 9) thusthe disc 65 can be caused to return automatically to its original 1position by moving the arm 62 to the left against the action of aspring, consequently disengaging the gear wheel 63 and allowing thesprin 67 to return the disc 65. Movement of the arm 62 is effected by acam 69 of oval or other elongated shape (which is seen end-on in Figure2) said cam being formed at the inner end of the spindle 10 of the knob26.

The mechanism further includes an interlocking device which willhereinafter be more fully described in connection with Figures 10 and11. Referring to Figure 2, however, it comprises briefly a bar 15 whichhas its left-hand end pivotally connected at T6 to an arm Tl adapted toswing freely about a stud 78. The opposite end of the bar 15 is pivotedat 19 to a locking arm mounted for free rotation about the axis of thegear wheel 46. The locking arm 80 is provided up on its underneath witha dog 8! of somewhat V- shaped cross-section, said dog being arranged,to be moved into engagement with the teeth of the gear wheel 44 so aspositively to prevent rotation of said gear wheel 44 and the windingknob '6. A dog upon the arm 11 co-operates in'a similar manner with aseries of notches 83 cut in the underneath part of the circumference ofthe disc 65, as will be clear from Figure 9. A bifurcated cam member 85pivotally mounted upon a screw 86 is arranged to be deflected by theoperation of the shutter and moves angularly an intermediate arm 84which is independently mounted upon the screw 86 and is coupled by a pinand slot connection 81 with the bar 15.

The general arrangement and operation of the shutter will be understoodmore clearly by reference to Figures 3 to 8 in conjunction with thefollowing explanation. The upper gear wheel 49 and the lower gear wheel4| are mounted coaxially, as will be seen more clearly in Figure 4, saidwheels being free to revolve independently and for convenience beingmounted loosely upon the spindle 53 with a spacing washer 88 betweenthem. Figure 4 shows clearly how the pinion 3B for winding the frontblind 32 is in permanent mesh with the wheel 49, while the correspondingpinion 39 belonging to the rear blind 33' is similarl in constant meshwith the lower gear wheel M. It should be mentioned that the spacing ofthe parts in a vertical direction has been considerabl exaggerated inFigure 4 for clarity,

but in practice said parts fit together to form a very compact assemblyhaving but little total depth. A peg 89 (shown in section in Figures 2and 3) is mounted firmly in the upper gear wheel and projects downwardstherefrom for engagement with a stop member 90 secured to a plate 9Iupon which the greater part of the mechanism shown in Figure 2 ismounted (see also Figure 9) the peg 89 also co-operates with a secondpeg 92 projecting upwards from the lower gear wheel 4I. The upper gearwheel 40 is formed with a series of holes 93 which are disposed at auniform radius but are spaced circumferentially at such intervals as tocorrespond with the periods of instantaneous exposure which the shutteris desired to make. Any one of these holes can be engaged by a pin 94secured to the flange 28 of the speed-setting knob 21, the arrangementbeing such that when the knob 21 is lifted against the action of acoiled compression spring 95 the pin 94 is released from the upper gearwheel 40 so that the knob 21 can then be rotated and the pin 94 insertedin the desired one of the holes 93. The function of this pin 94 is torelease the second blind, as will be explained hereinafter.

Mounted on top of the upper gear wheel 40 by means of a pair ofshouldered screws 96 is a quadrant-shaped deflector member 91 having anarcuate slot 98 adapted to slide upon the screws 96. The member 91 isurged normally in an anticlockwise direction by the free end of acurved'wire spring 99, which latter has its other end fastened to thegear wheel 40. At its leading end (i. e. the end which leads during thewinding of the shutter, when the wheel 40 is rotated clockwise) thedeflector member 91 is formed with a few spaced notches I00 serving todefine gear teeth between them. When the deflector member 91 is in itsnormal position (i. e. with the leading end of the slot 98 in engagementwith the corresponding screw 96) the first gear tooth, indicated attill, registers exactly with one of the teeth of the gear wheel 40; thenext few gear teeth of the wheel 40 (i. e. those beneath the deflectormember 91) are, however, out completely away, as indicated by the brokenline at 4041 in Figure 3. Owing to the fact that the full movement ofthe gear wheel 40 is only about three-quarters of a revolution, thiscut-away part 40a of the gear wheel 40 never comes into register withthe pinion 38. It will be noted that the notches I00 in the deflectormember 91 progressivel decrease in depth, and after a short distancefade out completely, so that beyond that point the outer curved surfaceof the deflector member 91 lies in register with the tips of the teethof the gear wheel 40.

The release lever 48, which is pivoted upon the screw 5|, is normallyurged forwards into engagement with the release plunger 3I by means of acoiled spring I02 having one limb anchored to the plate 9I at I03. Theother limb of this spring, bears against a lug I04 which is bentdownwards from the release lever 48 and which serves normally as a stopfor the first latch member 49. The latter, which is pivoted to the baseplate 9| by means of a screw I05, is urged to 'move angularly about thescrew I05 in a clockwise direction by means of a light spring (notshown), said first latch member 49 being provided with a roundedprojection I06 for engagement with the lug I04. The opposite end of thelatch member 49 is flat, as indicated at I 0! in Figure 5. The secondlatch member 50 is of the shape shown in Figure 6 and has a nose I08, anotch I09, and an upwardly directed tail IIO; the member 50 is alsourged resiliently so as to tend to move about the screw I05 in aclockwise direction under the action of a light spring (also not shown).It will be seen from Figure 3 that this tail H0 is normally arranged tobear against a cut-away portion I II of the release lever 48, but as theforce of the spring belonging to the latch member 50 is relativelylight, it is unable to shift the release lever 48 by overcoming thespring I02.

The operation of the shutter is as follows. When the shutter is in areleased condition the parts occupy the positions shown in Figure 3. Thepeg 89 of the upper gear wheel 40 is in engagement with the stop member90, while the peg 92 of the lower gear wheel 4| is in engagement withthe lower end of the peg 89', as will be seen also in Figure 4. Toprepare the camera for the next exposure the winding knob I6 (Figure 1)is turned in a clockwise direction, thus correspondingly rotating thespindle I1. This has a two-fold action; firstly it causes the gear wheel45 to drive the gear wheel 46 in an anti-clockwise direction, thuscommencing to wind up the fihn, and secondly it causes the gear wheel 44to rotate the driving gear wheel 42 in an anticlockwise direction, thuin turn rotating the upper gear wheel 40 in a clockwise direction. Itwill be seen that the spring I02 01 the release lever 48 acts throughthe link 52 so as to pull upon the arm 43 and maintain the gear wheel 42in firm driving contact with the gear wheel 40; the direction of thedrive also has this effect. It will be noted that the peg 89 of theupper gear wheel 40 causes the lower gear wheel M to be rotated inunison with the wheel 40 as it engages the peg 92 upon said lower gearwheel. As winding proceeds the parts reach the positions shown in Figure'1. The pegs 89 and 92 are in engagement with the first latch member 49and have slipped beyond the square end I01 thereof, the peg 92beingadjacent the nose I08 of the second latch member 59. It will beunderstood that the driving gear wheel 42 continues to rotate as thefihn is wound and it is therefore necessary for the drive to be impartedto the wheel 40 only up to the precise instant when the pegs 89 and 92reach the nose I03. It is for this reason that the deflector plate 91 isslidable upon the screws 96. Thus, as the winding of the shutter comesto an end with the peg 92 engaging the nose I08, the driving gear wheel42 has its teeth in mesh with the first few teeth Of the deflector plate91, and also in register with the gap 40a in the teeth of the wheel 40,Therefore continued rotation of the wheel 42 is not impeded by the wheel40, but instead the deflector plate 91 is moved by the driving gearwheel 42 to the position shown in Figure '7; the teeth of the gear wheel42 can then slide idly upon the ungrooved part of the defiector member91. The mechanism is so designed that when the shutter is in its fullywound condition, as shown in Figure 7, it will always be necessary towind the fihn a little further in order to bring the next picture areainto position, even when the end part of the fihn is being used, and inconsequence the effective diameter of the receiving film spool 20 isrelatively large. Therefore the winding of the knob I6 is continueduntil it is brought to a standstill by the interlocking means, as willbe hereinafter explained. Durin this additional winding, however, thegear wheel 42 rotates, but its teeth slip upon thelcurved faceofthedeflector member ,91', or at least ,upon that part of the memberwhere the .notches Hill are exceedingly shallow. The gear wheel 40 is ofcourse prevented from rotating iurther by the nose N38 or the latch 58,so that the deflector member 9'! slides forward upon the screws 96 tothe extent necessary in order to allow the slip-. ping of the gear wheel42 to occur. By adopting this arrangement the wear on the parts isexceedingly small, the gear wheel 40 can remain absolutely steady, andat'the same time the further winding of the film can take place with anxceptionally smooth action. If the operator should let go of the knob itwhen the shutter is partly wound but the pegs 89 and 92 have not reachedtheir final positions shown in Figure '7, then the pawl 4'! prevents theshutter mechanism from returning under the influence of the springrollers 34 and 35 of the blinds.

' Assumin that the shutter is set to make an instantaneous exposure, theefiect which occurs when the release plunger 3| is depressed is shown inFigure 8. It will be seen that the release lever 48 is moved in arearward direction (i. e. downwards in the drawings), and the firsteffect of this is to push upon the link 52, thus moving the arm 43angularly and disengaging the gear wheel 42 from the upper gear wheelincluding the deflector member 91. Then the lug I04 of the release levermoves the first latch member 49 in an anti-clockwise direction about theaxis of the screw H15. Thus the fiat end I01 moves clear of the peg 89(the upper gear wheel 43 is omitted from Figure 8, the peg B9 and thepin 94. both of which 'are carried by the wheel 40, beingshown insection), the gear wheel 40 conseouently being free to rotate rapidly inan anticlockwise direction as a result of the force imparted to it bythe front blind 32 through the medium of the pinion 38, which isindicated in dotted" lines in Figure 8. The peg'92 belonging to thelower gearwheel 4| is unable to follow suit, however, as the rearwardmovement of the release lever 48 enables the second latch member 50'also to move in a rearward direction under the influence of its spring,the tail llfl following up the movement of the release lever 48.Therefore the notch I08 catches the peg 92 and holds it in the positionshown in Figure 8. When the front blind has travelled a predetermineddistance, depending upon the position selected for the pin 94, thelatter strikes the right-hand rounded surface of the nose I 68 of thesecond latch member 50, thus causing the latter to be deflectedforwardly, its tail H0 leaving the release lever 48, This movement, ofcourse, frees the peg 92' belonging to the lower gear wheel 4| so thatsaid gear'w-heel is able to return to its released position at the sametime under the force imparted to'it by the rear blind 33. When the frontblind 32 finishes its travel the peg 89 has, of course, reached the stop90 and shortly afterwards the peg 92 similarly regains its releasedposition, as shown in Figure 3. Each of the blinds 32-and 33 is formedwith the usual aperture (not shown) which corresponds in size to thepicture area; these two apertures are arranged so that the aperture ofthe front blind 32 is in register with the picture area when the shutteris in its'released positionyand on the contrary the aperture in the rearblind 33 is in register ith the picture area when the shutter is fullywound. The actual time for which the film is exposed is regulated byvarying the effective width, of-the exposure slit in the blinds as is;common practice with focalplaneshuttersa If; the

pin 94 ha long way in front of-the peg 89, then the second blind 33 isreleased soon after the first blind, 32 and the overlap of the aperturesin the blinds is small, giving a short exposure. On the other hand byshifting the pin 94 backwards (in a clockwise direction) towards thepeg-19 the exposure is lengthened owing to the increased width of theslit. The travel of eachof the blinds is arranged so that the aperturesare out of register with one another during the winding operation, thusrendering the shutter selfcapping. V i

For brief exposures one of the holes 93 is so positioned that when thepin 94 is disposed there-. in it only reaches the position shown inFigure 8 by the time that the peg 89 engages the stopv 90. Therefore thesecond latch member 50 continues to remain operative so long as therelease plunger 3| is depressed. It will be seen thatin thesecircumstances the front blind 32 makes its full travel immediately theplunger 3! is depressed, thus bringing its aperture into register withthe picture area; in the meantime the rear blind 33- is still fullywound, so that its aperture is also in register with the picture areaand the film is therefore exposed over its whole picture area so 1621;;as the plunger 3| remains depressed. As soon, however, as the operatorlets go ofthe plunger 3| the release lever 48 moves forward under theaction of its spring I02, thus causing thesecon-d latch member 511to-bev moved forwards by its tail I I0 out of engagement with the peg92. Therefore, the lower gear wheel 4| is free to rotate anti-clockwise,thu allowing the rear blind 33 to assume its released position, andconsequently masking the picture area of the film. Thus the shutteropens fully as soon as the release plunger is depressed and remains openuntil such time as said plunger is released by. the operator. Extendedtime exposures can be obtained by providing a clas or the like (notshown) for the plunger 3|, said clasp being adapted to hold said plungerin the depressed condi. tion. Alternatively a flexible cable release ofthe usual type (not shown) can be inserted within a screw-threadedaperture H2 formed in the body iii (see Figure 2) so that the centralplunger or wire of said release co-operates with-the release lever 48.Suitable locking means can be provided on such a cable release forthepurpose of holding the latter in its depressed or operating conditionand thus efiectin "time exposures of any desired duration,

The action of the interlocking mechanism will now be described withparticular reference to Figures 2, l0 and 11. The bifurcated cam memberis rockable within limits on the screw 86 from one operative positionwhich is shown in Figure 2 to a second operative position which is shownin Figures 10 and 11. The cam member 85 is held firmly in each of thesepositions by a somewhat U-shaped wire spring 3, onelimb of which isturned over at its end to engage pivotally with a perforated lug I I4formed on the cam member 85; the other limb bears againstan abutment pinH5. It will bev seen that, as the arms of the spring I I3 tend to moveapart, said spring is arranged to urge the cam member 85, in eitherdirection away from it dead-centre position,

thereby holdin said cam member relatively firmly in either of its twooperative positions, -as mentioned above. A second and weaker wirespring I I8 is coiled around the screw 86, and has one end H6 anchoredto the cam member 85,

while its other end bears against a thrust pin I H! secured to theintermediate arm 84, the arrangement being such that the spring H8 tendsto move the intermediate arm 84 angularly towards the left about thescrew 86. The cam member 85 is provided with a stop projection H9, whichis arranged to co-operate with the thrust pin (see Figure 11). The armsof the cam member 85 are indicated at I29 and |2|; they are A inclinedto one another somewhat in the manner of the arms of a Y, their internalsurface being smoothly curved to the form shown. This surface isarranged to be engaged by a peg 8911,

which projects above the upper gear wheel 40 and constitutes acontinuation of the depending peg 89 (see Figure fl). 'Il'ms the pe 89a,in rotating with the Wheel 40, is able to flick the cam member 85 fromone operative position to the other during the use Of the shutter. Aspreviously mentioned, the dog 82 on the arm 11 is arranged to engagewith any one of the notches 83 in the indicator disc 65, and when theinterlocklng mechanism is in the appropriate position but there is nonotch 83 in register with the dog 82, then said dog merely rides againstthe curved circumferential surface between a pair of notches 83. It willalso be remembered that the dog 8| on the arm 88 is adapted to engagewith the teeth of the gear wheel 44 and thus prevent the rotation of thelatter when the do 82 is engaged with a notch 83.

The action of the interlocking mechanism is as follows. After anexposure has been made by the release of the shutter the parts are inthe positions shown in Figure 2. It will be noted that the cam member 85is in its rearmost operating position and that the stop projection H9 isin engagement with the thrust pin I I1, thus urging the intermediate arm84 to the right and holding both of the dogs 82 and 8| in theirinoperative positions owing to the action of the dead-centre spring H3.As the shutter is wound by operation of the knob Hi, the gear wheel 49is rotated in a clockwise direction so that the peg 89a, upon the top ofthe wheel 48 moves alongside the arm 52] of the cam member 85 and thenengages the surface of the arm I29 of said cam member, which surfaceisoblique to, and crosses the pathof, the peg 99a. This shifts the cammember 85 to the position shown in Figure 10. When the shutter is fullywound, of course, the peg 89a occupies a position just beyond the fiatend of the first latch member 49, as shown. The movement of the cammember 85 to its forward position shifts the stop projection H9 andtherefore allows the intermediate arm 84 to move as far as it cantowards the left under the influence of the relatively weak spring I I8.Although the film is being wound simultaneously with the shutter, at thetime when the cam member 85 is moved to the position shown in Figure 10the next picture area of the film will not have arrived in positionready for exposure; nevertheless the indicator disc 65 will have movedan appreciable distance (corresponding to the distance which the filmhas moved) and therefore the dog 82 will be unable to return to itsoriginal notch 83. As a consequence it merely rests lightly upon thecircumference of the indicator disc 65 and so holds the dog 8| out ofengagement with the gear wheel 44, the parts then being in the positionsindicated in Figure 10. As winding of the film proceeds the indicatordisc 65 continuesto rotate, and at the the next notch 83 reaches the dog82, which latter drops into said notch under the action of the springH8. This brings the dog 8| into engagement with the teeth of the gearwheel 44 and so prevents further rotation of the winding knob i6. Whenthe shutter is released to make the next exposure, the gear wheel 49rotates anticlockwise, as above described, and the peg 89a, carriedthereby slides against the arm |2| of the cam member thus deflectingoutwards the arm |2| thereof and returning the cam member 85 to theposition shown in Figure 2. During this movement of the cam member 85the stop projection H9 engages the thrust pin H1, and causes theintermediate arm 84 and the bar 15 to be moved to the right, sodisengaging the dogs BI and 82 from the gear wheel 44 and the indicatordisc 65, respectively.

At the beginning of a daylight loading roll film package, as at presentsupplied, is a length of paper backing strip which has to be wound on tothe receiving spool 29 so as to bring the first picture area of the filminto the correct position for exposure. In order to prevent interferenceby the interlocking mechanism while this is being done, the knob 26 isturned through a right angle from the position shown in thefigures,'thus causing the cam 69 to spread apart the adjacent ends ofthe lever 62 and arm 11, for it will be remembered that the cam 69 is ofelongated shape. This movement of the lever 62 to the left disengagesthe pinion 63 from the gear wheel 64, thus allowing the spring 61 toreturn the indicator disc 65 to its 1 position (if necessary). Thus asthe said backing strip is drawn forward it turns idly the roller 2| andthe gear wheels 6|, 63. The action of the cam 69 on the arm 11 is tohold the dogs 8| and 82 positively out of engagement with the gear wheel44 and indicator disc 65, respectively; as the shutter is being woundthe cam member 65 is, of course, moved to its forward position (as inFigures 10 and 11) thus stressing the spring H8, which latter urges thedogs 8| and 82' into the engaged positions as soon as the knob 26 isturned to bring the cam 69 to its normal position when the first picturearea of the film is in its proper position for exposure. Similarly, whenthe last exposure has been made, the knob 26 is again turned through aright angle to release the interlocking means and enable the roll filmto be fully wound and removed from the camera; at the same time therelease of the lever 62 automatically returns the indicator disc 85 toits 1 position. If desired the cam 69 can be so shaped that when turnedin one direction from its normal position it moves the arm 11 todisengage the interlocking means in order to enable the film to be woundinto its starting position, or wound off; when turned to its otherposition, the cam 69 would move the lever 62 so as to enable theindicator disc 65 to return to its 1 position. v

It will be apparent that the winding of the film serves to wind theshutter through the gear wheels 44', 42 and 40 and that the shutter iscompletely wound by the time that the pegs 89 and 92 reach the nose 5!]as shown in Figure 7. Up to this point it is necessary that the gearwheel 48 be positively rotated to the stated position, and at this pointthe wheels must separate so that further rotation of the driving gearwheel will take place freely. Heretofore the means for securing thisresult is to cut away several of the teeth of the wheel as of saidwheel. avoided by the use of-adeflector plate fixedly elated thatunder'such an arrangement the last tooth of the wheel '48 would receivevery rough treatment fromv the driving gear wheel 42, for

said last tooth would be urged by the springs of both blinds intorubbing engagement with the driving wheel 42 during'the continuedrotation While this difficulty might be mounted on the driven gear wheel42, such arrangement would of necessity disengage the gear wheelsgradually so that it would not be certain that the pegs 89 and'92 wouldjust reach the nose 50 and then stop precisely, at the same timepermitting the driving gear wheel 42 to continue in operation. If, as inthe present invention, the

deflector-plates! is made separate from the gear wheel 49, and mountedto-be movable circumferentially, it is possible for' the whole of theunmeshingof the gear teeth to take place after the rotation of the wheel40 itself has ceased. This ensures that the wheel 40 is moved decisivelyto bring the pegs 89 and 92 into engagement with the nose 5!] beforethedeflector plate comes into action, moving the wheels apart.

2,392,071 -40 at the requiredposition, but it will be a prethe'proiection to be positioned-so that, even after type, with or withoutthe combined film Winding mechanism, and the film-actuated mechanicalindicating device. Such an indicating device, however, has the advantagethat, after the film has once been wound to bring the first picture areainto position for exposure, using the usual nonactinic window in theback of the camera, the

indicator can be set to its 1 position, and thereafter said window canremain covered until the next film is being inserted. The mechanicalindicator is, of course, used as a guide toshow when eachsuccessivepicture area has been fully wound into position, that is in cases whereautomatic interlocking mechanism is not provided.

What we claim is:

1. A camera shutter comprising a pair of apertured roller blindsarranged to be wound against spring influence with the apertures out ofregister, the apertures in the blinds being arranged so that they bothregister. with the picture area when the first blind is completelyreleased and the second blind is fully wound, a pair of meshing gearwheels for winding said blinds, means urging said gear wheels intoengagement with one another, which means act resiliently so as to allowthe wheel axes to move apart and the driving wheel to slip when thedriven wheel reaches a predetermined position, a deflector member whichis mounted slidabl upon the driven gear wheel so as to movecircumferentially relative thereto and which, when the driven gear wheelreaches the said predetermined position during the winding of theshutter, is engaged by the driving gear wheel, and is moved therebyrelative to the driven gear wheel to shift the axes of the gear wheelsapart and unmesh the teeth thereof, a projection operated by the firstblind, and a pair of latch members, the first of which holds both blindsuntil it is moved to its'released position, whereupon the second latchmember holds the second blind .until the said second latch member ismoved to release the second blind, provision being made for the fiilltravel of the first blind has taken place, said projection does notreach the second latch member, so that after the first latch member hasbeen released the shutter remains fully open until the second latchmember is released manually.

2. In a camera shutter as defined in claim 1,

wherein apertured spring roller blinds arearranged to be wound andreleased one after the other to produce an exposure, the provision -ofexposure-setting means comprising a projection which releases the secondblind and which is constituted by the tipof a release pin, which latteris adapted to be inserted into any one of a series of holes formed in awheel at positions which are equi-dis'tant from the centre of saidwheel.

3. A camera as claimed in claim 1, wherein winding means for the rollerblinds-comprises an :angularly'movablearm, a driving gear wheel carriedby said arm, a driven gear wheel, resilient means urging the arm so thatthe driving gear wheel meshes with the driven gear wheel, and meansconnecting the arm with the release member whereby the said gear wheelsare completely disengaged when the release member is operated to releasethe shutter.

4. In a camera shutter, winding mechanism comprising a driving gearwheel, a driven gear wheel, resilient means acting to urge the axes ofthe driving and driven gear wheels towards one another to bring theirteeth into mesh, a deflector member mounted upon the driven wheel tohave limited circumferential movement relative thereto, said deflectormember being arranged to overlap the teeth of the driven gear wheel andhaving an operative surface which is engageable by the teeth of thedriving gear as the driven gear wheel reaches a predetermined positionin the winding of the shutter, and the teeth of the driven gear Wheelbeing cut away to form a gap overlapped by the deflector member, wherebythe driving gear wheel rotates the driven gear wheel until the latterreaches the said predetermined position, continued rotation of thedriving gear wheel causing the deflector member to movecircumferentially around the driven gear wheel and at the same timeshift the driving gear wheel in a direction away from the axis of thedriven gear wheel.

5. A camera shutter as defined in claim 4, wherein the operative surfaceof the deflector member is formed with a series of notches defining gearteeth, that notch first engaged by the driving gear wheel during thewinding of the shutter being substantially equal in size to the teeth ofthe driven gear wheel and successive notches being reduced in depth soas to lead the driving gear wheel smoothly into engagement with anun-notched part of the said operative surface.

6. A camera shutter as defined in claim 4, wherein the deflector membercomprises a plate having an arcuate slot concentric with the axis of thedriven gear wheel, a pair of pins projecting from said driven gear wheelbeing in engagement the driving gear wheel into mesh with the drivengear wheel, the axis of which latter is fixed.

9. In a camera shutter, a pair of meshing gear wheels which are used forwinding the shutter, means for urging said gear wheels into engagement,which means act resiliently so as to allow the wheel axes to move apartand the driving wheel to slip when the driven wheel reaches apredetermined position, and a deflector member which is mounted upon thedriven gear wheel so as to move circumferentially relative thereto andwhich, when the driven gear wheel reaches the said predeterminedposition during the winding of the shutter, is engaged by the drivinggear wheel, and is moved thereby relative to the driven gear wheel toshift the axes of the gear wheels apart and un-mesh the teeth thereof.

10. A camera shutter comprising a pair of overlapping spring rollerblinds, each formed with an aperture, a pair of meshing gear wheels forwinding said blinds, means urging said gear wheels into engagement withone another, which means act resiliently so as to allow the wheel axesto move apart and the driving wheel to slip when the driven wheelreaches a predetermined position corresponding to the full winding ofthe blinds, and a deflector member which is mounted slidably upon thedriven gear wheel so as to move circumferentially relative thereto andwhich, when the driven gear wheel reaches the said predeterminedposition during the winding of the shutter, is engaged by the drivinggear wheel and is moved thereby relative to the driven gear wheel toshift the axes of the gear wheels apart and un-mesh the teeth thereof.

JOSEPH TERRETT.

WILLIAM BARTON WOOD.

